Electronic and optical properties of 4.2 μm"N" structured superlattice MWIR photodetectors
Author
Salihoglu, O.
Hostut M.
Tansel, T.
Kutluer, K.
Kilic A.
Alyoruk, M.
Sevik, C.
Turan, R.
Ergun, Y.
Aydınlı, Atilla
Date
2013Source Title
Infrared Physics and Technology
Print ISSN
1350-4495
Publisher
Elsevier
Volume
59
Pages
36 - 40
Language
English
Type
ArticleItem Usage Stats
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Abstract
We report on the development of a new structure for type II superlattice photodiodes that we call the "N" design. In this new design, we insert an electron barrier between InAs and GaSb in the growth direction. The barrier pushes the electron and hole wavefunctions towards the layer edges and under bias, increases the overlap integral by about 25% leading to higher detectivity. InAs/AlSb/GaSb superlattices were studied with density functional theory. Both AlAs and InSb interfaces were taken into account by calculating the heavy hole-light hole (HH-LH) splittings. Experiments were carried out on single pixel photodiodes by measuring electrical and optical performance. With cut-off wavelength of 4.2 μm at 120 K, temperature dependent dark current and detectivity measurements show that the dark current is 2.5 × 10 -9 A under zero bias with corresponding R0A resistance of 1.5 × 104 Ω cm2 for the 500 × 500 μm2 single pixel square photodetectors. Photodetector reaches BLIP condition at 125 K with the BLIP detectivity (DBLIP) of 2.6 × 10 10 Jones under 300 K background and -0.3 V bias voltage. © 2012 Elsevier B.V. All rights reserved.
Keywords
Barrier designInfrared detector
MWIR photodetector
N structure
SiO2 passivation
Superlattice
Barrier design
Cutoff wavelengths
Electronic and optical properties
Hole wave functions
Optical performance
Overlap integrals
Temperature dependent
Type-II superlattices
Chemical bonds
Density functional theory
Infrared detectors
Molecular orbitals
Optical properties
Photodetectors
Photodiodes
Photons
Pixels
Superlattices
Wave functions
Structural design